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1.
Nat Metab ; 6(2): 290-303, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38316982

RESUMO

Obesity is a major public health crisis. Multi-specific peptides have emerged as promising therapeutic strategies for clinical weight loss. Glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) are endogenous incretins that regulate weight through their receptors (R). AMG 133 (maridebart cafraglutide) is a bispecific molecule engineered by conjugating a fully human monoclonal anti-human GIPR antagonist antibody to two GLP-1 analogue agonist peptides using amino acid linkers. Here, we confirm the GIPR antagonist and GLP-1R agonist activities in cell-based systems and report the ability of AMG 133 to reduce body weight and improve metabolic markers in male obese mice and cynomolgus monkeys. In a phase 1, randomized, double-blind, placebo-controlled clinical study in participants with obesity ( NCT04478708 ), AMG 133 had an acceptable safety and tolerability profile along with pronounced dose-dependent weight loss. In the multiple ascending dose cohorts, weight loss was maintained for up to 150 days after the last dose. These findings support continued clinical evaluation of AMG 133.


Assuntos
Peptídeo 1 Semelhante ao Glucagon , Agonistas do Receptor do Peptídeo 1 Semelhante ao Glucagon , Camundongos , Animais , Humanos , Masculino , Peptídeo 1 Semelhante ao Glucagon/uso terapêutico , Redução de Peso , Peptídeos/uso terapêutico , Obesidade/tratamento farmacológico , Obesidade/metabolismo
2.
Andrology ; 10(4): 789-799, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35224888

RESUMO

BACKGROUND: Glucose-dependent insulinotropic polypeptide receptor (Gipr) gene expression has been reported in mouse spermatids and Gipr knockout male mice have previously been reported to have decreased in vitro fertilization, although the role of Gipr signaling in male mouse fertility is not well understood. OBJECTIVES: The purposes of these studies were to determine the role of glucose-dependent insulinotropic polypeptide receptor in male fertility using Gipr knockout mice and anti-glucose-dependent insulinotropic polypeptide receptor antibody-treated wild-type mice and to determine if the expression of Gipr in mouse testes is similar in non-human and human primates. METHODS AND MATERIALS: Adiponectin promoter-driven Gipr knockout male mice (GiprAdipo-/- ) were assessed for in vitro and in vivo fertility, sperm parameters, and testicular histology. CD1 male mice were administered an anti-glucose-dependent insulinotropic polypeptide receptor antibody (muGIPR-Ab) prior to and during mating for assessment of in vivo fertility and sperm parameters. Expression of Gipr/GIPR mRNA in the mouse, cynomolgus monkey, and human testes was assessed by in situ hybridization methods using species-specific probes. RESULTS: GiprAdipo-/- male mice are infertile in vitro and in vivo, despite normal testis morphology, sperm counts, and sperm motility. In contrast, administration of muGIPR-Ab to CD1 male mice did not impact fertility. While Gipr mRNA expression is detectable in the mouse testes, GIPR mRNA expression is not detectable in monkey or human testes. DISCUSSION: The infertility of GiprAdipo-/- male mice correlated with the lack of Gipr expression in the testis and/or adipocyte tissue. However, as administration of muGIPR-Ab did not impact the fertility of adult male mice, it is possible that the observations in genetically deficient male mice are related to Gipr deficiency during development. CONCLUSION: Our data support a role for Gipr expression in the mouse testis during the development of sperm fertilization potential, but based on gene expression data, a similar role for glucose-dependent insulinotropic polypeptide receptor in non-human primate or human male fertility is unlikely.


Assuntos
Polipeptídeo Inibidor Gástrico , Testículo , Animais , Feminino , Fertilidade , Polipeptídeo Inibidor Gástrico/genética , Polipeptídeo Inibidor Gástrico/metabolismo , Expressão Gênica , Humanos , Macaca fascicularis/genética , Macaca fascicularis/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , RNA Mensageiro/metabolismo , Receptores Acoplados a Proteínas G/genética , Receptores dos Hormônios Gastrointestinais , Motilidade dos Espermatozoides , Testículo/metabolismo
3.
Cell Rep Med ; 2(5): 100263, 2021 05 18.
Artigo em Inglês | MEDLINE | ID: mdl-34095876

RESUMO

Glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) regulate glucose and energy homeostasis. Targeting both pathways with GIP receptor (GIPR) antagonist antibody (GIPR-Ab) and GLP-1 receptor (GLP-1R) agonist, by generating GIPR-Ab/GLP-1 bispecific molecules, is an approach for treating obesity and its comorbidities. In mice and monkeys, these molecules reduce body weight (BW) and improve many metabolic parameters. BW loss is greater with GIPR-Ab/GLP-1 than with GIPR-Ab or a control antibody conjugate, suggesting synergistic effects. GIPR-Ab/GLP-1 also reduces the respiratory exchange ratio in DIO mice. Simultaneous receptor binding and rapid receptor internalization by GIPR-Ab/GLP-1 amplify endosomal cAMP production in recombinant cells expressing both receptors. This may explain the efficacy of the bispecific molecules. Overall, our GIPR-Ab/GLP-1 molecules promote BW loss, and they may be used for treating obesity.


Assuntos
Peso Corporal/fisiologia , Peptídeo 1 Semelhante ao Glucagon/metabolismo , Obesidade/metabolismo , Receptores dos Hormônios Gastrointestinais/antagonistas & inibidores , Animais , Polipeptídeo Inibidor Gástrico/metabolismo , Peptídeo 1 Semelhante ao Glucagon/farmacologia , Receptor do Peptídeo Semelhante ao Glucagon 1/metabolismo , Teste de Tolerância a Glucose/métodos , Haplorrinos/metabolismo , Camundongos Obesos
4.
Mol Metab ; 46: 101117, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33220493

RESUMO

BACKGROUND: Obesity is rapidly becoming one of the world's most critical health care concerns. Comorbidities accompanying excess weight include cardiovascular disease, diabetes, and certain cancers. These comorbidities result in greater hospitalization and other health care-related costs. Economic impacts are likely to be felt more acutely in developing countries, where obesity rates continue to rise and health care resources are already insufficient. Some of the more effective treatments are invasive and expensive surgeries, which some economies in the world cannot afford to offer to a broad population. Pharmacological therapies are needed to supplement treatment options for patients who cannot, or will not, undergo surgical treatment. However, the few drug therapies currently available have either limited efficacy or safety concerns. A possible exception has been glucagon-like peptide-1 analogs, although these have shown a number of adverse events. New drug therapies that are safe and produce robust weight loss are needed. SCOPE OF REVIEW: Herein, we review the role of growth differentiation factor 15 (GDF15) in feeding behavior and obesity, summarize some of the new and exciting biological discoveries around signaling pathways and tissue sites of action, and highlight initial efforts to develop GDF15-based therapies suitable for inducing weight loss in humans. MAJOR CONCLUSIONS: Within the last several years, great strides have been made in understanding the biology of GDF15. Recent developments include identification of an endogenous receptor, biological localization of the receptor system, impact on energy homeostasis, and identification of molecules suitable for administration to humans as anti-obesity treatments. New and exciting research on GDF15 suggests that it holds promise as a novel obesity treatment as new molecules progress toward clinical development.


Assuntos
Fator 15 de Diferenciação de Crescimento/farmacocinética , Fator 15 de Diferenciação de Crescimento/uso terapêutico , Obesidade/tratamento farmacológico , Obesidade/metabolismo , Animais , Peso Corporal/efeitos dos fármacos , Ingestão de Alimentos , Receptores de Fator Neurotrófico Derivado de Linhagem de Célula Glial , Fator 15 de Diferenciação de Crescimento/genética , Fator 15 de Diferenciação de Crescimento/metabolismo , Humanos , Resistência à Insulina , Redução de Peso/efeitos dos fármacos
5.
Nat Commun ; 11(1): 4981, 2020 10 05.
Artigo em Inglês | MEDLINE | ID: mdl-33020469

RESUMO

Antagonism or agonism of the glucose-dependent insulinotropic polypeptide (GIP) receptor (GIPR) prevents weight gain and leads to dramatic weight loss in combination with glucagon-like peptide-1 receptor agonists in preclinical models. Based on the genetic evidence supporting GIPR antagonism, we previously developed a mouse anti-murine GIPR antibody (muGIPR-Ab) that protected diet-induced obese (DIO) mice against body weight gain and improved multiple metabolic parameters. This work reconciles the similar preclinical body weight effects of GIPR antagonists and agonists in vivo, and here we show that chronic GIPR agonism desensitizes GIPR activity in primary adipocytes, both differentiated in vitro and adipose tissue in vivo, and functions like a GIPR antagonist. Additionally, GIPR activity in adipocytes is partially responsible for muGIPR-Ab to prevent weight gain in DIO mice, demonstrating a role of adipocyte GIPR in the regulation of adiposity in vivo.


Assuntos
Adipócitos/efeitos dos fármacos , Fármacos Antiobesidade/farmacologia , Receptores dos Hormônios Gastrointestinais/agonistas , Receptores dos Hormônios Gastrointestinais/antagonistas & inibidores , Adipócitos/metabolismo , Tecido Adiposo/efeitos dos fármacos , Tecido Adiposo/metabolismo , Animais , Fármacos Antiobesidade/química , Fármacos Antiobesidade/uso terapêutico , Anticorpos/farmacologia , Anticorpos/uso terapêutico , Peso Corporal/efeitos dos fármacos , Membrana Celular/metabolismo , Células Cultivadas , AMP Cíclico/metabolismo , Dieta Hiperlipídica/efeitos adversos , Ácidos Graxos/metabolismo , Polipeptídeo Inibidor Gástrico/farmacologia , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Obesidade/tratamento farmacológico , Obesidade/metabolismo , Obesidade/patologia , Receptores dos Hormônios Gastrointestinais/deficiência , Receptores dos Hormônios Gastrointestinais/metabolismo
6.
J Lipid Res ; 61(12): 1764-1775, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33008925

RESUMO

Of the known regulators of atherosclerosis, miRNAs have been demonstrated to play critical roles in lipoprotein homeostasis and plaque formation. Here, we generated a novel animal model of atherosclerosis by knocking in LDLRW483X in C57BL/6 mice, as the W483X mutation in LDLR is considered the most common newly identified pathogenic mutation in Chinese familial hypercholesterolemia (FH) individuals. Using the new in vivo mouse model combined with a well-established atherosclerotic in vitro human cell model, we identified a novel atherosclerosis-related miRNA, miR-23a-3p, by microarray analysis of mouse aortic tissue specimens and human aortic endothelial cells (HAECs). miR-23a-3p was consistently downregulated in both models, which was confirmed by qPCR. Bioinformatics analysis and further validation experiments revealed that the TNFα-induced protein 3 (TNFAIP3) gene was the key target of miR-23a-3p. The miR-23a-3p-related functional pathways were then analyzed in HAECs. Collectively, the present results suggest that miR-23a-3p regulates inflammatory and apoptotic pathways in atherogenesis by targeting TNFAIP3 through the NF-κB and p38/MAPK signaling pathways.


Assuntos
Aterosclerose/genética , Aterosclerose/patologia , MicroRNAs/genética , Animais , Apoptose , Modelos Animais de Doenças , Células Endoteliais/patologia , Feminino , Camundongos , Transdução de Sinais
7.
MAbs ; 12(1): 1710047, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31905038

RESUMO

Glucose-dependent insulinotropic polypeptide (GIP) is an incretin hormone involved in regulating glucose and lipid metabolism. GIP receptor (GIPR) antagonism is believed to offer therapeutic potential for various metabolic diseases. Pharmacological intervention of GIPR, however, has limited success due to lack of effective antagonistic reagents. Previously we reported the discovery of two mouse anti-murine GIPR monoclonal antibodies (mAbs) with distinctive properties in rodent models. Here, we report the detailed structural and biochemical characterization of these two antibodies, mAb1 and mAb2. In vitro and in vivo characterizations demonstrated mAb2 is a full GIPR antagonistic antibody and mAb1 is a non-neutralizing GIPR binder. To understand the molecular basis of these two antibodies, we determined the co-crystal structures of GIPR extracellular domain in complex with mAb1 and with mAb2 at resolutions of 2.1 and 2.6 Å, respectively. While the non-neutralizing mAb1 binds to GIPR without competing with the ligand peptide, mAb2 not only partially occludes the ligand peptide binding, but also recognizes the GIPR C-terminal stalk region in a helical conformation that acts as a molecular mimic of the ligand peptide and locks GIPR in a novel auto-inhibited state. Furthermore, administration of mAb2 in diet-induced obesity mice for 7 weeks leads to both reduction in body weight gain and improvement of metabolic profiles. In contrast, mAb1 has no effect on body weight or other metabolic improvement. Together, our studies reveal the unique molecular mechanism of action underlying the superior antagonistic activity of mAb2 and signify the promising therapeutic potential of effective GIPR antagonism for the treatment of metabolic disorders.


Assuntos
Anticorpos Monoclonais/química , Anticorpos Monoclonais/farmacologia , Receptores dos Hormônios Gastrointestinais/antagonistas & inibidores , Aumento de Peso/efeitos dos fármacos , Animais , Dieta Hiperlipídica/efeitos adversos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Obesidade/etiologia , Obesidade/metabolismo , Conformação Proteica
8.
Endocr Rev ; 41(1)2020 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-31511854

RESUMO

Glucose-dependent insulinotropic polypeptide receptor (GIPR) is associated with obesity in human genome-wide association studies. Similarly, mouse genetic studies indicate that loss of function alleles and glucose-dependent insulinotropic polypeptide overexpression both protect from high-fat diet-induced weight gain. Together, these data provide compelling evidence to develop therapies targeting GIPR for the treatment of obesity. Further, both antagonists and agonists alone prevent weight gain, but result in remarkable weight loss when codosed or molecularly combined with glucagon-like peptide-1 analogs preclinically. Here, we review the current literature on GIPR, including biology, human and mouse genetics, and pharmacology of both agonists and antagonists, discussing the similarities and differences between the 2 approaches. Despite opposite approaches being investigated preclinically and clinically, there may be viability of both agonists and antagonists for the treatment of obesity, and we expect this area to continue to evolve with new clinical data and molecular and pharmacological analyses of GIPR function.


Assuntos
Fármacos Antiobesidade/uso terapêutico , Terapia de Alvo Molecular , Obesidade/tratamento farmacológico , Receptores dos Hormônios Gastrointestinais/antagonistas & inibidores , Animais , Estudo de Associação Genômica Ampla , Humanos , Camundongos , Terapia de Alvo Molecular/métodos , Terapia de Alvo Molecular/tendências , Obesidade/genética , Receptores dos Hormônios Gastrointestinais/genética , Receptores dos Hormônios Gastrointestinais/fisiologia
9.
Sci Transl Med ; 10(472)2018 12 19.
Artigo em Inglês | MEDLINE | ID: mdl-30567927

RESUMO

Glucose-dependent insulinotropic polypeptide (GIP) receptor (GIPR) has been identified in multiple genome-wide association studies (GWAS) as a contributor to obesity, and GIPR knockout mice are protected against diet-induced obesity (DIO). On the basis of this genetic evidence, we developed anti-GIPR antagonistic antibodies as a potential therapeutic strategy for the treatment of obesity and observed that a mouse anti-murine GIPR antibody (muGIPR-Ab) protected against body weight gain, improved multiple metabolic parameters, and was associated with reduced food intake and resting respiratory exchange ratio (RER) in DIO mice. We replicated these results in obese nonhuman primates (NHPs) using an anti-human GIPR antibody (hGIPR-Ab) and found that weight loss was more pronounced than in mice. In addition, we observed enhanced weight loss in DIO mice and NHPs when anti-GIPR antibodies were codosed with glucagon-like peptide-1 receptor (GLP-1R) agonists. Mechanistic and crystallographic studies demonstrated that hGIPR-Ab displaced GIP and bound to GIPR using the same conserved hydrophobic residues as GIP. Further, using a conditional knockout mouse model, we excluded the role of GIPR in pancreatic ß-cells in the regulation of body weight and response to GIPR antagonism. In conclusion, these data provide preclinical validation of a therapeutic approach to treat obesity with anti-GIPR antibodies.


Assuntos
Receptor do Peptídeo Semelhante ao Glucagon 1/agonistas , Obesidade/tratamento farmacológico , Receptores dos Hormônios Gastrointestinais/antagonistas & inibidores , Adipócitos/metabolismo , Animais , Anticorpos/farmacologia , Anticorpos/uso terapêutico , Dieta , Quimioterapia Combinada , Comportamento Alimentar , Polipeptídeo Inibidor Gástrico/metabolismo , Receptor do Peptídeo Semelhante ao Glucagon 1/metabolismo , Peptídeos Semelhantes ao Glucagon/análogos & derivados , Peptídeos Semelhantes ao Glucagon/farmacologia , Peptídeos Semelhantes ao Glucagon/uso terapêutico , Humanos , Fragmentos Fc das Imunoglobulinas/farmacologia , Fragmentos Fc das Imunoglobulinas/uso terapêutico , Células Secretoras de Insulina/efeitos dos fármacos , Células Secretoras de Insulina/metabolismo , Liraglutida/farmacologia , Liraglutida/uso terapêutico , Camundongos Obesos , Obesidade/patologia , Primatas , Receptores dos Hormônios Gastrointestinais/metabolismo , Proteínas Recombinantes de Fusão/farmacologia , Proteínas Recombinantes de Fusão/uso terapêutico , Respiração , Aumento de Peso/efeitos dos fármacos , Redução de Peso/efeitos dos fármacos
10.
Sci Transl Med ; 9(412)2017 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-29046435

RESUMO

In search of metabolically regulated secreted proteins, we conducted a microarray study comparing gene expression in major metabolic tissues of fed and fasted ob/ob mice and C57BL/6 mice. The array used in this study included probes for ~4000 genes annotated as potential secreted proteins. Circulating macrophage inhibitory cytokine 1 (MIC-1)/growth differentiation factor 15 (GDF15) concentrations were increased in obese mice, rats, and humans in comparison to age-matched lean controls. Adeno-associated virus-mediated overexpression of GDF15 and recombinant GDF15 treatments reduced food intake and body weight and improved metabolic profiles in various metabolic disease models in mice, rats, and obese cynomolgus monkeys. Analysis of the GDF15 crystal structure suggested that the protein is not suitable for conventional Fc fusion at the carboxyl terminus of the protein. Thus, we used a structure-guided approach to design and successfully generate several Fc fusion molecules with extended half-life and potent efficacy. Furthermore, we discovered that GDF15 delayed gastric emptying, changed food preference, and activated area postrema neurons, confirming a role for GDF15 in the gut-brain axis responsible for the regulation of body energy intake. Our work provides evidence that GDF15 Fc fusion proteins could be potential therapeutic agents for the treatment of obesity and related comorbidities.


Assuntos
Fator 15 de Diferenciação de Crescimento/uso terapêutico , Obesidade/tratamento farmacológico , Animais , Cristalografia por Raios X , Dependovirus/metabolismo , Dieta , Preferências Alimentares , Esvaziamento Gástrico , Fator 15 de Diferenciação de Crescimento/química , Humanos , Macaca fascicularis , Masculino , Camundongos Endogâmicos C57BL , Camundongos Obesos , Neurônios/fisiologia , Obesidade/patologia , Ratos Sprague-Dawley , Receptores Fc/metabolismo , Proteínas Recombinantes de Fusão/metabolismo , Regulação para Cima
11.
J Bone Miner Res ; 32(4): 834-845, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-27505721

RESUMO

Results of prior studies suggest that fibroblast growth factor 21 (FGF21) may be involved in bone turnover and in the actions of peroxisome proliferator-activated receptor (PPAR) α and γ in mice. We have conducted independent studies to examine the effects of FGF21 on bone homeostasis and the role of FGF21 in PPARα and γ actions. High-fat-diet-induced obesity (DIO) mice were administered vehicle or recombinant human FGF21 (rhFGF21) intraperitoneally at 0 (vehicle), 0.1, 1, and 3 mg/kg daily for 2 weeks. Additional groups of DIO mice received water or 10 mg/kg rosiglitazone daily. Mice treated with rhFGF21 or rosiglitazone showed expected metabolic improvements in glucose, insulin, and lipid levels. However, bone loss was not detected in rhFGF21-treated mice by dual-energy X-ray absorptiometry (DXA), micro-CT, and histomorphometric analyses. Mineral apposition rate, a key bone formation parameter, was unchanged by rhFGF21, while significantly decreased by rosiglitazone in DIO mice. Bone resorption markers, OPG/RANKL mRNA expression, and histological bone resorption indices were unchanged by rhFGF21 or rosiglitazone. Bone marrow fat was unchanged by rhFGF21, while increased by rosiglitazone. Furthermore, FGF21 knockout mice did not show high bone mass phenotype. Treatment with PPARα or PPARγ agonists caused similar metabolic effects in FGF21 knockout and wild-type mice. These results contrast with previous findings and suggest that FGF21 is not critical for bone homeostasis or actions of PPARα and PPARγ. © 2016 American Society for Bone and Mineral Research.


Assuntos
Densidade Óssea , Fatores de Crescimento de Fibroblastos , Regulação da Expressão Gênica/efeitos dos fármacos , Homeostase , PPAR alfa , PPAR gama , Animais , Densidade Óssea/efeitos dos fármacos , Densidade Óssea/genética , Gorduras na Dieta/efeitos adversos , Gorduras na Dieta/farmacologia , Fatores de Crescimento de Fibroblastos/genética , Fatores de Crescimento de Fibroblastos/metabolismo , Fatores de Crescimento de Fibroblastos/farmacologia , Glucose/metabolismo , Homeostase/efeitos dos fármacos , Homeostase/genética , Humanos , Insulina/genética , Insulina/metabolismo , Masculino , Camundongos , Camundongos Knockout , Obesidade/induzido quimicamente , Obesidade/metabolismo , Osteoprotegerina/biossíntese , Osteoprotegerina/genética , PPAR alfa/agonistas , PPAR alfa/biossíntese , PPAR alfa/genética , PPAR gama/agonistas , PPAR gama/biossíntese , PPAR gama/genética , Ligante RANK/biossíntese , Ligante RANK/genética , Rosiglitazona , Tiazolidinedionas/farmacologia
12.
PLoS One ; 10(6): e0126924, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26083576

RESUMO

Trefoil factor 3 (TFF3), also called intestinal trefoil factor or Itf, is a 59 amino acid peptide found as a homodimer predominantly along the gastrointestinal tract and in serum. TFF3 expression is elevated during gastrointestinal adenoma progression and has been shown to promote mucosal wound healing. Here we show that in contrast to other trefoil factor family members, TFF1 and TFF2, TFF3 is highly expressed in mouse duodenum, jejunum and ileum and that its expression is regulated by food intake. Overexpression of TFF3 using a recombinant adeno-associated virus (AAV) vector, or daily administration of recombinant TFF3 protein in vivo improved glucose tolerance in a diet-induced obesity mouse model. Body weight, fasting insulin, triglyceride, cholesterol and leptin levels were not affected by TFF3 treatment. Induction of mucinous metaplasia was observed in mice with AAV-mediated TFF3 overexpression, however, no such adverse histological effect was seen after the administration of recombinant TFF3 protein. Altogether these results suggest that the therapeutic potential of targeting TFF3 to treat T2D may be limited.


Assuntos
Glicemia/metabolismo , Ingestão de Alimentos/genética , Vetores Genéticos/efeitos adversos , Metaplasia/genética , Mucinas/genética , Obesidade/genética , Animais , Colesterol/sangue , Dependovirus/genética , Dieta Hiperlipídica , Duodeno/metabolismo , Duodeno/patologia , Expressão Gênica , Regulação da Expressão Gênica , Vetores Genéticos/química , Vetores Genéticos/metabolismo , Teste de Tolerância a Glucose , Humanos , Íleo/metabolismo , Íleo/patologia , Insulina/sangue , Jejuno/metabolismo , Jejuno/patologia , Leptina/sangue , Masculino , Metaplasia/etiologia , Metaplasia/metabolismo , Metaplasia/patologia , Camundongos , Mucinas/administração & dosagem , Mucinas/metabolismo , Obesidade/etiologia , Obesidade/metabolismo , Obesidade/patologia , Proteínas Recombinantes/administração & dosagem , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Transdução de Sinais , Fator Trefoil-2 , Fator Trefoil-3 , Triglicerídeos/sangue
13.
PLoS One ; 8(4): e61432, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23630589

RESUMO

The endocrine hormone FGF21 has attracted considerable interest as a potential therapeutic for treating diabetes and obesity. As an alternative to the native cytokine, we generated bispecific Avimer polypeptides that bind with high affinity and specificity to one of the receptor and coreceptor pairs used by FGF21, FGFR1c and ß-Klotho. These Avimers exhibit FGF21-like activity in in vitro assays with potency greater than FGF21. In a study conducted in obese male cynomolgus monkeys, animals treated with an FGFR1c/ß-Klotho bispecific Avimer showed improved metabolic parameters and reduced body weight comparable to the effects seen with FGF21. These results not only demonstrate the essential roles of FGFR1c and ß-Klotho in mediating the metabolic effects of FGF21, they also describe a first bispecific activator of this unique receptor complex and provide validation for a novel therapeutic approach to target this potentially important pathway for treating diabetes and obesity.


Assuntos
Fármacos Antiobesidade/farmacologia , Fatores de Crescimento de Fibroblastos/fisiologia , Proteínas de Membrana/antagonistas & inibidores , Obesidade/tratamento farmacológico , Peptídeos/farmacologia , Receptor Tipo 1 de Fator de Crescimento de Fibroblastos/antagonistas & inibidores , Sequência de Aminoácidos , Animais , Fármacos Antiobesidade/farmacocinética , Sítios de Ligação , Ligação Competitiva , Peso Corporal/efeitos dos fármacos , Linhagem Celular , Avaliação Pré-Clínica de Medicamentos , Fatores de Crescimento de Fibroblastos/química , Insulina/sangue , Proteínas Klotho , Macaca fascicularis , Masculino , Proteínas de Membrana/biossíntese , Camundongos , Mimetismo Molecular , Dados de Sequência Molecular , Obesidade/sangue , Peptídeos/farmacocinética , Ligação Proteica , Ratos , Receptor Tipo 4 de Fator de Crescimento de Fibroblastos/química , Proteínas Recombinantes de Fusão/antagonistas & inibidores , Proteínas Recombinantes de Fusão/biossíntese , Albumina Sérica/farmacocinética , Albumina Sérica/farmacologia , Transdução de Sinais , Triglicerídeos/sangue
14.
J Pharmacol Exp Ther ; 331(3): 871-81, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19720878

RESUMO

Uncontrolled hepatic glucose output (HGO) contributes significantly to the pathological hyperglycemic state of patients with type 2 diabetes. Glucagon, through action on its receptor, stimulates HGO, thereby leading to increased glycemia. Antagonizing the glucagon signaling pathway represents an attractive therapeutic approach for the treatment of type 2 diabetes. We previously reported the generation and characterization of several high-affinity monoclonal antibodies (mAbs) targeting the glucagon receptor (GCGR). In the present study, we demonstrate that a 5-week treatment of diet-induced obese mice with mAb effectively normalized nonfasting blood glucose. Similar treatment also reduced fasting blood glucose without inducing hypoglycemia or other undesirable metabolic perturbations. In addition, no hypoglycemia was found in db/db mice that were treated with a combination of insulin and mAb. Long-term treatment with the mAb caused dose-dependent hyperglucagonemia and minimal to mild alpha-cell hyperplasia in lean mice. There was no evidence of pancreatic alpha-cell neoplastic transformation in mice treated with mAb for as long as 18 weeks. Treatment-induced hyperglucagonemia and alpha-cell hyperplasia were reversible after treatment withdrawal for periods of 4 and 10 weeks, respectively. It is noteworthy that pancreatic beta-cell function was preserved, as demonstrated by improved glucose tolerance throughout the 18-week treatment period. Our studies further support the concept that long-term inhibition of GCGR signaling by a mAb could be an effective approach for controlling diabetic hyperglycemia.


Assuntos
Anticorpos Monoclonais/uso terapêutico , Células Secretoras de Glucagon/patologia , Glucagon/sangue , Glucose/metabolismo , Hiperglicemia/tratamento farmacológico , Hipoglicemiantes/uso terapêutico , Receptores de Glucagon/antagonistas & inibidores , Animais , Anticorpos Monoclonais/administração & dosagem , Anticorpos Monoclonais/efeitos adversos , Glicemia , Diabetes Mellitus Experimental/sangue , Diabetes Mellitus Experimental/tratamento farmacológico , Diabetes Mellitus Experimental/metabolismo , Hiperglicemia/sangue , Hiperglicemia/metabolismo , Hiperplasia , Hipoglicemia/sangue , Hipoglicemia/metabolismo , Hipoglicemia/prevenção & controle , Hipoglicemiantes/administração & dosagem , Hipoglicemiantes/efeitos adversos , Insulina/administração & dosagem , Insulina/uso terapêutico , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Obesidade/sangue , Obesidade/metabolismo , Taquifilaxia
15.
Am J Physiol Endocrinol Metab ; 297(5): E1105-14, 2009 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19706786

RESUMO

Recombinant fibroblast growth factor (FGF)21 has antihyperglycemic, antihyperlipidemic, and antiobesity effects in diabetic rodent and monkey models. Previous studies were confined to measuring steady-state effects of FGF21 following subchronic or chronic administration. The present study focuses on the kinetics of biological actions of FGF21 following a single injection and on the associated physiological and cellular mechanisms underlying FGF21 actions. We show that FGF21 resulted in rapid decline of blood glucose levels and immediate improvement of glucose tolerance and insulin sensitivity in two animal models of insulin resistance (ob/ob and DIO mice). In ob/ob mice, FGF21 led to a 40-60% decrease in blood glucose, insulin, and amylin levels within 1 h after injection, and the maximal effects were sustained for more than 6 h despite the 1- to 2-h half-life of FGF21. In DIO mice, FGF21 reduced fasting blood glucose and insulin levels and improved glucose tolerance and insulin sensitivity within 3 h of treatment. The acute improvement of glucose metabolism was associated with a 30% reduction of hepatic glucose production and an increase in peripheral glucose turnover. FGF21 appeared to have no direct effect on ex vivo pancreatic islet insulin or glucagon secretion. However, it rapidly induced typical FGF signaling in liver and adipose tissues and in several hepatoma-derived cell lines and differentiated adipocytes. FGF21 was able to inhibit glucose release from H4IIE hepatoma cells and stimulate glucose uptake in 3T3-L1 adipocytes. We conclude that the acute glucose-lowering and insulin-sensitizing effects of FGF21 are potentially associated with its metabolic actions in liver and adipose tissues.


Assuntos
Tecido Adiposo/metabolismo , Fatores de Crescimento de Fibroblastos/farmacologia , Hipoglicemiantes , Resistência à Insulina/fisiologia , Fígado/metabolismo , Células 3T3-L1 , Adipócitos/efeitos dos fármacos , Tecido Adiposo/efeitos dos fármacos , Animais , Área Sob a Curva , Western Blotting , Diferenciação Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Dieta , Relação Dose-Resposta a Droga , Ensaio de Imunoadsorção Enzimática , Fatores de Crescimento de Fibroblastos/farmacocinética , Técnica Clamp de Glucose , Humanos , Polipeptídeo Amiloide das Ilhotas Pancreáticas/metabolismo , Ilhotas Pancreáticas/efeitos dos fármacos , Ilhotas Pancreáticas/metabolismo , Fígado/efeitos dos fármacos , Neoplasias Hepáticas Experimentais/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Obesos , Obesidade/metabolismo , Proteínas Recombinantes/farmacologia
16.
Pathogenetics ; 2(1): 1, 2009 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-19161594

RESUMO

BACKGROUND: C57BLKS/J (BLKS) mice are susceptible to islet exhaustion in insulin-resistant states as compared with C57BL6/J (B6) mice, as observed by the presence of the leptin receptor (Lepr) allele, Leprdb/db. Furthermore, DBA2/J (DBA) mice are also susceptible to beta-cell failure and share 25% of their genome with BLKS; thus the DBA genome may contribute to beta-cell dysfunction in BLKS mice. RESULTS: Here we show that BLKS mice exhibit elevated insulin secretion, as evidenced by improved glucose tolerance and increased islet insulin secretion compared with B6 mice, and describe interstrain transcriptional differences in glucose response. Transcriptional differences between BLKS and B6 mice were identified by expression profiling of isolated islets from both strains. Genomic mapping of gene expression differences demonstrated a significant association of expression differences with DBA loci in BLKS mice (P = 4x10-27). CONCLUSION: Two genes, Nicotinamide nucleotide transhydrogenase (Nnt) and Pleiomorphic adenoma gene like 1 (Plagl1), were 4 and 7.2-fold higher respectively in BLKS islets, and may be major contributors to increased insulin secretion by BLKS islets. Contrary to reports for B6 mice, BLKS mice do not harbor a mutant Nnt gene. We detected 16 synonymous polymorphisms and a two-amino acid deletion in the Plagl1 gene in BLKS mice. Several inflammatory glucose-responsive genes are expressed at a higher level in BLKS, suggesting an inflammatory component to BLKS islet dysfunction. This study describes physiological differences between BLKS and B6 mice, and provides evidence for a causative role of the DBA genome in beta-cell dysfunction in BLKS mice.

17.
J Lipid Res ; 50(3): 534-545, 2009 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18974039

RESUMO

We conducted a genome-wide screen using the mutagen N-ethyl-N-nitrosourea to identify recessive mutations in genes that lead to altered lipid traits in mice. We screened 7,546 G3 mice that were of mixed C57BL/6J (B6) x C3.SW-H2(b)/SnJ (C3) genomes and identified three pedigrees with differences in plasma HDL-cholesterol. Genome scan analyses mapped three distinct loci to chromosomes 3, 4, and 7. An S1748L missense mutation was identified in ABCA1 in one pedigree with undetectable levels of HDL-cholesterol and resulted in reduced protein levels. This phenotype was completely penetrant, semi-dominant, and cosegregated with high plasma triglycerides. Mice in a second pedigree had very high levels of plasma total cholesterol and HDL-cholesterol (up to 800 mg/dl total cholesterol). Despite a high degree of phenotype lability and reduced penetrance, an I68N missense mutation was identified in the transcription factor CCAAT/enhancer binding protein alpha (C/EBPalpha). Finally, a second high HDL-cholesterol pedigree of mice, again with a highly labile phenotype and reduced penetrance, was mapped to a 7 Mb locus on chromosome 3. These results illustrate the use of a hybrid background for simultaneous screening and mapping of mutagenized pedigrees of mice and identification of three novel alleles of HDL-cholesterol phenotypes.


Assuntos
HDL-Colesterol/sangue , HDL-Colesterol/genética , Genes Recessivos , Mutação , Transportador 1 de Cassete de Ligação de ATP , Transportadores de Cassetes de Ligação de ATP/genética , Animais , Sequência de Bases , Proteína alfa Estimuladora de Ligação a CCAAT/genética , Colesterol/deficiência , Mapeamento Cromossômico , DNA/genética , Etilnitrosoureia/toxicidade , Feminino , Testes Genéticos , Hiperlipoproteinemia Tipo II/sangue , Hiperlipoproteinemia Tipo II/genética , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Mutantes , Mutagênese , Mutagênicos/toxicidade , Mutação de Sentido Incorreto , Fenótipo , Polimorfismo de Nucleotídeo Único
18.
Diabetes ; 55(7): 2042-50, 2006 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-16804074

RESUMO

Fasting hyperglycemia, a prominent finding in diabetes, is primarily due to increased gluconeogenesis. The transcription factor Foxo1 links insulin signaling to decreased transcription of PEPCK and glucose-6-phosphatase (G6Pase) and provides a possible therapeutic target in insulin-resistant states. Synthetic, optimized antisense oligonucleotides (ASOs) specifically inhibit Foxo1 expression. Here we show the effect of such therapy on insulin resistance in mice with diet-induced obesity (DIO). Reducing Foxo1 mRNA expression with ASO therapy in mouse hepatocytes decreased levels of Foxo1 protein and mRNA expression of PEPCK by 48 +/- 4% and G6Pase by 64 +/- 3%. In mice with DIO and insulin resistance, Foxo1 ASO therapy lowered plasma glucose concentration and the rate of basal endogenous glucose production. In addition, Foxo1 ASO therapy lowered both hepatic triglyceride and diacylglycerol content and improved hepatic insulin sensitivity. Foxo1 ASO also improved adipocyte insulin action. At a tissue-specific level, this manifested as improved insulin-mediated 2-deoxyglucose uptake and suppression of lipolysis. On a whole-body level, the result was improved glucose tolerance after an intraperitoneal glucose load and increased insulin-stimulated whole-body glucose disposal during a hyperinsulinemic-euglycemic clamp. In conclusion, Foxo1 ASO therapy improved both hepatic insulin and peripheral insulin action. Foxo1 is a potential therapeutic target for improving insulin resistance.


Assuntos
Fatores de Transcrição Forkhead/genética , Insulina/fisiologia , Fígado/fisiologia , Oligonucleotídeos Antissenso , Animais , Glicemia/metabolismo , Proteína Forkhead Box O1 , Fatores de Transcrição Forkhead/antagonistas & inibidores , Fatores de Transcrição Forkhead/deficiência , Cinética , Camundongos , Transaminases/metabolismo
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